Hi there
S2000 is not bad at all. Its like anything if your going to press on in the wet then be ready to catch her as they will let go if your too heavy on the throttle. Drive it smoothly in the wet and drive at a speed safe for the condition then its not gonna bite you.
I had a 99 spec S2000, which are regarded as the worse as they are very snappy due to the GEO setup etc.
I believe 2000 onwards cars were a little tamer, 2002 models got a bit tamer again and in 2004 onwards they were made a lot more friendly.
Seriously a blue or black S2000 2004 onwards look awsome. Superb handling, quite raw but could be made even rawer and power upgrades come in the form of superchargers which is something you could save up for or just buy a 2002 car cheap as a project.
S2000 hands down for hot sunny days.
M3 E46 for all other days.
It will be a hard choice.